use the CTM for non-scaling-stroke rather than the screen CTM
Differential Revision: https://phabricator.services.mozilla.com/D211581
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1898409
gecko-commit: 8be119d3c4a47600746cefadd42695820dba8a12
gecko-reviewers: emilio